This invention relates to injectors and particularly to gas-gas injectors utilizing linear capillary orifices.
It is well known that injectors for chemical lasers commonly utilize doublet or triplet injectors that by proper orifice orientation effectuate impingement of the two fluids for achieving mixing. These heretoknown injectors inherently produce a high turbulence of the reaction products in the combustion chamber with a consequential heat loss to the chamber walls.
We have found that we can achieve a more efficacious injector which is particularly advantageous in a chemical laser application by utilizing capillary orifices sized to provide a sonic flow. The streams of gases to be reacted are placed into parallel flow relationship at different velocities which expand as free jets until they react with each other achieving shear mixing. The orifices are arranged in linear arrays to provide uniform temperature profiles along vertical lines.
Among the advantages of this invention, although not limited thereto, are:
1. Very high injection element density along the linear array;
2. Very uniform temperature and species profile along the linear array;
3. When utilized in a two stage reaction process, the capability to place the linear arrays from the first stage as near to each other as necessary to align with the linear nozzle arrays utilized in the second stage is enhanced.
4. Optimum arrangement of the injection elements for various reactant combinations; 5. Incorporation of capillary tube injector elements into a solid face, one piece injector body so that the high velocity gas provides sufficient cooling for the injector face without supplemental cooling;
6. Sonic injection velocity at normal injector pressure drops giving absolute isolation from feed system coupling and a very high velocity ratio for improved shear mixing;
7. Good isolation from feed system coupling at subsonic injection velocities because of the high frictional pressure loss;
8. Elimination of the very small orifices (0.001" diameter for these flowrates) which would be required if conventional short orifices were used.